4.2.4. In Diphthong

1. There are long diphthongs -au, -eu, -ou, -ei, which sometimes present short vowels, as well as other endings without diphthong, i.e., -a, -e, -o.

NOTE. The last are probably remains of older diphthongs, from IE II. So, although from the point of view of the Indo-European there are only stems with variants -au, -eu, -a, etc, these can all be classified as Diphthong endings, because the original stems were formed as diphthongs in the language history. This kind of irregularities is usual in today's languages, as it was already five millennia ago.

In zero grade, in Genitive, there are forms with -i- or -ij- or with -u- or -uw-, depending on the diphthongs.

SINGULAR

m. cou

m. djeu

NOM.

cous

djeus

ACC.

com

djem, dijem

VOC.

cou

djeu

GEN.

cous

diuos, djeues

OBL.

cowi

djeuei

2. These are root words, but there is a secondary formation of words, especially that of Greek origin, in -eus, -euos, as in Avestic bazaus, arm, or gr. Basileus, which are also so declined.